This discussion paper resulted in a chapter in (P. Nijkamp, J. Poot, M. Sahin (Eds.)) <I>Migration Impact Assessment: New Horizons</I>, 2012 (KNAW sponsored).<P> The concentration of people with diverse socio-cultural backgrounds in particular geographic areas may boost the creation of new ideas,...</p></i>

Prior research suggests that start-up costs and taxes negatively influence entry into entrepreneurship. Yet, no distinction is made regarding the type of entrepreneurship, particularly innovative versus non-innovative entrepreneurship. Start-up costs, being one-off costs, may reduce the entry of...

In recent decades there have been an enormous number of studies about innovation systems, partly inspired by a great interest among policy makers in search for a solid scientific foundation and professional support to identify appropriate development strategies. Despite different perspectives,...

Portuguese strategic choices regarding innovation and R&D policy have, over the past two decades, produced various positive achievements, in which the regions of Lisbon and Algarve have taken the lead, and are the only ones in the country to converge towards the European average growth rate....

We study a two-stage R&D project with an abandonment option. Two types of uncertainty influence the decision to start R&D. Demand uncertainty is modelled as a lottery between a proportional increase and decrease in demand. Technical uncertainty is modelled as a lottery between a decrease and...

This discussion paper resulted in a publication in the <I>Journal of Economic Dynamics and Control</I> (2013), 37(12), 2729-2754.<P> Existing models of R&D are not easily reconciled with four observable aspects of R&D: initial technologies ('ideas') need to be developed further, only a minority of initial...</p></i>

We present a continuous-time generalization of the seminal R&D model of d’Aspremont and Jacquemin (American Economic Review, Vol. 78, No. 5) to examine the trade-off between the benefits of allowing firms to cooperate in R&D and the corresponding increased potential for product market...

The importance of knowledge spillovers for achieving innovation and economic growth is widely recognized. It is not straightforward which type of spillovers is most effective: intra-sectoral spillovers or inter-sectoral spillovers. We investigate this controversy using a model of regional...

We analyze the impact of obsolescence of economic inventions by incorporating maintenance costsin the endogenous growth model of expanding product varieties. This contrasts with the existingliterature, which ignores maintenance costs and uses the model of quality improvements todescribe...

Finding proper policy instruments to promote productivity growth features prominently on the Lisbon agenda and is central in many national as well as European policy debates. In view of the increased mobility of high-skilled workers in Europe, ongoing globalization and increased interregional...